MLA

Murphy, Gerald, 1888-1964. "C" general. Box 1, folder 19. 1918-1964, undated. https://collections.library.yale.edu/catalog/32308265.

APA, 6th edition

Murphy, Gerald, 1888-1964. (["Box 1, folder 19"])(1918-1964, undated)["C" general]. https://collections.library.yale.edu/catalog/32308265.